Internal combustion engines combust an air and fuel mixture within cylinders of the engine to produce drive torque. Engines can include a turbocharger that increases torque output by delivering additional air into the cylinders. One traditional turbocharger includes a variable nozzle turbo (VNT). VNT's include variable position vanes that regulate the amount of air delivered through the VNT. The vane position ranges from a fully-open position to a fully-closed position. In the fully-open position, the VNT delivers a minimum amount of air to the engine. In the fully-closed position, the VNT delivers a maximum amount of air to the engine. The vanes can be positioned between the fully-open and fully-closed positions to provide an intermediate amount of air to the engine. A vane solenoid adjusts the vane position based on a control signal and a vane position sensor generates a signal indicating the actual vane position for feedback control.
In general engine components, such as the vane solenoid, are affected by temperature. Traditionally, temperature sensors are incorporated at or near critical engine components to monitor temperature. In components such as VNTs, including a temperature sensor increases cost (e.g., cost of the sensor itself, wiring, packaging, etc.) and complexity. Further, because such components normally do not include temperature sensors, temperature based diagnostics and/or remedial actions are not included in traditional engine control systems.